Vulture

ABOUT

What makes a vulture?They may not be the prettiest birds of prey, but the world would be a smellier place without vultures!

All vultures have a wide wingspan, which allows them to soar for long periods of time without flapping so much as a feather while looking for carrion to eat. They all have a sharp, hooked beak for ripping apart meat. Vultures are large compared to other birds. Their bald head and neck serve a useful purpose, allowing vultures to steer clear of infection and tangled feathers when eating decaying meat. A strong immune system allows vultures to eat rotting and possibly infected meat without getting sick.

These unusual birds are divided into two groups: New World vultures, which are from North, Central, and South America; and Old World vultures, which live in Africa, Asia, and Europe.

New World vultures have a distinctive bald head, an adaptation that helps reduce the risks of disease, because bacteria could become lodged in feathers, while the bald head and neck may be disinfected by the sun’s rays. New World vultures have nostrils that are long and horizontal, with a space between them. They do not have a voice box, so they cannot make any sound except hisses and grunts. New World vultures don’t build nests; instead, they lay their eggs in holes on high rocky surfaces or in tree cavities.

Old World vultures look like their eagle and hawk relatives. They have large, grasping talons, a voice box to vocalize with, and build nests made of sticks on rocky platforms or in trees. Old World vultures have also been around longer than the New World vultures. They have stronger feet than the New World vultures, which have feet that are not designed for grasping, and large, broad wings that allow them to stay aloft for most of the day, and a large, powerful beak with a hooked tip.

Some other examples of Old World vultures are Himalayan, Egyptian, hooded, Indian black, and palm-nut vultures, and Egyptian or Eurasian griffons.

Although New World vultures are unable to make more than hissing and grunting sounds, Old World vultures can be quite vocal when feeding at a carcass, making lots of grunts, croaks, screeches, and chatter. White-backed vultures croak plaintively or squeal like pigs during a meal. Bearded vultures scream while rolling and twisting in flight during courtship.

Not many animals threaten vultures. Covered as they are with bacteria, they would make most predators sick if eaten. Other scavengers may threaten the vulture, mainly to get better access to a shared carcass. Vultures tend to gorge themselves, often to the point of being unable to fly. If they feel bothered as they stand about digesting their food, they simply regurgitate to lighten the load and fly off.

Many people look at the vulture as a sign of death, but some cultures admire the birds. Ancient Egyptians connected the Egyptian griffon to their goddess Nekhbet, guardian of mothers and children. Griffon images are found in early Egyptian paintings and drawings and even had a place on the crown of the pharaoh, alongside the cobra. In Native American culture, California condors are important in mythology and burial rituals.

Vultures are also important in India, as they help remove dead animals without spreading disease. In other parts of Asia, religious and cultural traditions call for the carcasses of domestic animals to be left out for “disposal” by vultures. In some regions, even human remains are left out for the vultures prior to burial.

Vultures may not have the cleanest job, but you will never hear them complaining!

HABITAT AND DIET

Home is where the food is! Vultures are pretty flexible when it comes to their habitat, as long as there is food, although you won’t find them in Australia, polar regions, or most small islands. They are pretty adaptable in different environments.

Vultures are scavengers. They usually eat carrion, although sometimes they attack newborn or wounded animals. It seems that once food is located, the information is relayed rapidly to other vultures in the vicinity. Once one vulture lands, many more land and join in the feast. Because vultures are generally quiet, it is likely that the information is passed visually by behavioral cues for one bird to another until a regular orgy of eating begins.

Vultures tend to look at any meal as a Thanksgiving meal, so they eat as much as they can, because they never know when they will find their next meal—and it could be as long as two weeks before they do! Like many other birds, vultures have a throat pouch called a crop that can store food for eating at a later time or can be regurgitated to feed to their young.

Different vulture species have their own flair for getting their food, and their ability to use “tools” to get that food is unique among birds. The Egyptian vulture breaks open ostrich eggs by dropping stones on them. Lammergeier or bearded vultures carry bones into the air and drop them onto favored rocky areas to break them open; the birds then fly down to eat the nutritional marrow inside, using their specialized tongue. In Africa, many different vulture types gather at a carcass to eat, but there is a pecking order: larger vultures get to eat first while the smaller ones wait their turn.

Turkey vultures are found all over North and South America, found in open country, woodlands, farms, and in our backyard at the San Diego Zoo Safari Park! They are about 27 inches (70 centimeters) tall and have a wingspan of about 5.6 feet (1.7 meters). These vultures have a big, dark-brown body, a red, bald head, and pink legs and feet. They hunt for their food by smell, feast in groups, and prefer only the tender meat. Turkey vultures are a very important part of North America’s cleanup crew.

At the San Diego Zoo and San Diego Zoo Safari Park, the vultures are fed rabbits, rats, cow spleen, oxtails, and a fortified meat-based commercial carnivore diet.

FAMILY LIFE

By day, vultures spend their time in the sky searching for carrion. Unlike other raptors that must be able to maneuver quickly to swoop down on prey, vultures only have to stay in flight for hours at a time, high enough to have a good field of vision to spot food. They’re specially built for this task with a huge expanse of wing feathers and a short tail. They rarely flap their wings, preferring to soar gracefully on air currents. If they hit a warm pocket of air in the sky, called a wind thermal, some vultures have the ability to soar for hours without once flapping their wings!

At night, they settle down to roost. White-backed vultures roost in a tree with a group of 10 or 12 others. Bearded or lammergeier vultures live in groups of up to 25 birds. Ruppell’s griffons are social creatures that live in colonies that may have as many as 1,000 pairs; the colony is noisy in the evening with its members’ loud, harsh calls. Turkey vultures are only social when roosting; their roost may be a single, large tree used year after year.

Vultures try to attract a mate by soaring in the sky around each other. The male shows off his flying skills by almost touching the female’s wing tip as he flies by to impress her. Normally, vultures are social birds that hunt in flocks, but when it comes to starting a family, they pair for life. Old World vultures make a nest in an overhung ledge, rocky crag, or tree, constructed with sticks and perhaps lined with grass. New World vultures don’t bother with nest making at all and merely lay their egg(s) in a cave or under a rocky overhang, on the ground under bushes or rock piles, or in tree hollows or fallen logs.

The mother vulture lays one egg, typically, if she is one of the larger species, two eggs if she is one of the smaller vulture species. Both parents work as a team to incubate and feed the chicks. Of course, chicks don’t drink milk; instead, the parent regurgitates meat into the chick’s mouth to feed it.

When the chick is young the parents pick up small pieces of food and feed them to the chick, but as it gets older, it picks up these regurgitated food items on its own. Chicks remain in the nest for two to three months and continue to depend on their parents for a period of time after fledging, until they learn how to find and compete for food on their own. By the time they are ready to fledge, at three to six months old, the chicks are nearly the same size as their parents and are fully feathered, but their coloration is different.

AT THE ZOO

Vultures of all types have been in San Diego Zoo Global’s collection since our earliest days, starting with turkey and king vultures in the early 1920s and black vultures in 1926. Two Egyptian vultures arrived at the Zoo in 1947.

In the 1930s, a Southern California resident found a vulture nest and took its two chicks, which he believed to be California condors. The youngsters were confiscated by authorities and brought to our Zoo when they were a bit older, where it was determined that they were turkey vultures. We released them back into the wild when we felt they were old enough to venture out on their own. However, a few days later, we noticed that there were a lot of vultures hanging out in our trees, and one of them kept trying to get in our vulture aviary—it was one of the youngsters, and it had alerted its friends that there was free food to be had!

In 1982, as we geared up to help save the highly endangered California condor, we honed our husbandry techniques on Andean condors as well as king, turkey, and black vultures in the San Diego Zoo Safari Park’s newly built “Condorminium” complex. One local wild turkey vulture squeezed under and around fencing and gates to be inside with the Andean condors! He was soon placed in a room of his own that featured a specially prepared diet brought to him, the company of kin, and the opportunity, whenever he wanted, to exercise his wings.

Today, both the San Diego Zoo and San Diego Zoo Safari Park have Andean and California condors. In addition, the Safari Park is home to several Old World vulture species: Ruppell’s and lappet-faced vultures can be seen from the Africa Tram tour; hooded and Egyptian vultures are on exhibit in Africa Woods. The Park has been successful in breeding many vulture species over the years: king, Ruppell’s, and hooded vultures, and Andean and California condors. Our Condor Cam gives viewers a look at a Calfornia condor family at the Park.

Despite the vulture’s seemingly messy eating habits, it is a clean bird and bathes frequently. You may see our vultures bathing in their exhibit pool. Some of them even like getting doused with the hose by their keepers!

You may also see wild turkey vultures that hang around the Safari Park. They have excellent eyesight and can easily spot a keeper walking to an exhibit with a “free lunch.”

CONSERVATION

Things we humans put in our environment seem to be causing rapid declines in vulture populations. For example, in India and other parts of South Asia in the 1990s, huge numbers of vultures died. In 2000, San Diego Zoo Global joined the investigation to determine what was killing the birds. The outcome surprised everyone: an anti-inflammatory drug used by veterinarians and ranchers to help livestock. The vultures were eating livestock that had been treated by the drug, became sick, and died. Efforts were made to restrict the use of the drug in livestock.

Poachers in Africa and Asia are known to poison the carcasses of elephants they have killed, after they take the tusks, to kill any vultures that come to clean up the mess, believing the gathering birds might reveal the scene of the crime. Ranchers frustrated by large cat attacks on their livestock poison cattle carcasses to kill the carnivores, but the poison also kills the vultures that come to pick the carcass clean. And vultures die from eating meat killed by hunters using lead bullets; the birds slowly die from lead poisoning. A study done in southern Africa revealed that about 25 percent of the white-backed vultures Gyps africanus tested had high levels of lead in their blood.

To conserve these graceful scavengers, breeding programs, education, and awareness programs have been started for endangered vultures by organizations like The Peregrine Fund and Vulture Rescue. San Diego Zoo Global is significantly involved in the California Condor Recovery Program.

There are people fighting for these birds, and so can you! Place trash in the right bin, don’t use dangerous chemicals, dispose of harmful substances responsibly, and recycle. If you are a hunter, please use non-lead bullets. These are all ways that you can help wildlife, including those misunderstood vultures.